Question

57×12+57×3-57×5的简便计算

57×12+57×3-57×5的简便计算

Answer 1

①55-（6.82+15.55）=55-22.37=32.63②52-17.87-12.23=52-（17.87+12.23）=52-30.1=21.9③57+3.17+3.43+5.83=（57+3.43）+（3.17+5.83）=60.43+9=69.43④75-8.64-3.36=75-（8.64+3.36）=75-12=63⑤83-9.5-7.83-0.5=83-7.83-（9.5+0.5）=75.17-10=65.17⑥45+8.7+16.55+1.3=45+16.55+（8.7+1.3）=61.55+10=71.55⑦54-5.96=54-（6-0.04）=54-6+0.04=48+0.04=48.04⑧38-5.34+2.62-4.66=（38+2.62）-（5.34+4.66）=40.62-10=30.62⑨63-（8.5+9.63）=63-18.13=44.87

Answer 2

57×12+57×3-57×5
=57x(12+3-5)
=57x10
=570